The sweat is still drying on his face as, with a white towel around his bare neck, Steve Nash revels in a famous victory for his favourite team. Having just inspired the Phoenix Suns to an easy win over the Chicago Bulls, so strengthening their lead in the NBA's Pacific Division, Nash is surrounded by giant basketball players in various stages of swaggering nudity. But, lost in his own world, he grins helplessly at his sporting memory of the year so far.

"We played pretty well the last two games against them and got nothing," he says softly in a quiet corner of the Suns' locker room. "So to win 5-1 was amazing. We can forget all about the hoodoo now, concentrate on the final and just have something to celebrate again. I think we deserved it after all those years of pain against Arsenal."

The "we" of whom Nash speaks so passionately are his beloved Tottenham Hotspur and the score that means so much to the man who has been the NBA's Most Valuable Player two out of the past three seasons is their drubbing of Arsenal in the Carling Cup semi-final last month. The lone regret for Nash is that, on the night Spurs were beating their arch rivals for the first time this century, he was in Milwaukee preparing for a routine NBA win.

"We were on the road again," he sighs of the draining 82 games his team endures during the regular season before they even begin the play-offs for an NBA championship. "I saw the goals and the celebrations afterwards and it was great. It feels like a long time since we were in a final."

Last October, in the New York Times, Nash first expressed his public desire to become something more than just a perennial football supporter. "I'd like to be an owner [of Spurs]," he said. "It's something I could do for the rest of my life."

Nash, one of the more obviously intelligent stars of world sport, pauses when asked if that dream remains - even if, in a more likely scenario, he would be part of a consortium in charge of Spurs. "Yeah," he says slowly before, more persuasively, revealing his enthusiasm again. "Yeah! Yeah! I'm completely behind the group that's there now and I love what's going on at Spurs at the moment. But I would definitely love to be part of Spurs once my [basketball] career is over. I've got plenty on my plate right now and so I can't imagine exactly how it might work but it's a big goal of mine."

The 34-year-old Nash earns $11m (£5.65m) a year in Phoenix but does not have the personal fortune to consider buying Tottenham. "At this stage I'm just in casual contact with [the Spurs chairman] Daniel Levy and [the director of football] Damien Comolli and we're not necessarily speaking about how I might get involved. They know how much the club means to me but at this point it's more a friendship than a business partnership."

If Levy and Comolli move on, Nash insists that "nothing will change from my perspective. Spurs are my club no matter what happens".

That sincere ardour is distinct from the profit-fuelled objectives of most American hustlers in the Premier League. Nash, who disconcerted media outlets in the US by speaking out against the war in Iraq and by reading the Communist Manifesto and Alexander Solzhenitsyn, raises a brow at the takeovers of Manchester United and Liverpool by, respectively, the Glazer family and Tom Hicks and George Gillett. "Unlike them, I've been a passionate supporter all my life. My parents are from north London and so it's not like I'm some Yank who wants to make a profit out of football. I don't care about making money. I just want to see Spurs succeed and, if I can help, that's great."

Nash was recently named in Time magazine's list of the 100 most influential people in the world - which, if nothing else, highlights his power in America. It also encourages him to say, in his low-key way, that "maybe there are some relationships I can help Spurs with, in terms of contacts and people in the North American market. That would be the obvious thing for me to offer to the club at this stage".

On Sunday Tottenham face Chelsea at Wembley. Although there is a seven-hour time difference between Phoenix and London, the Suns are playing just after noon local time so Nash's hopes of watching the Carling Cup final on cable TV are overshadowed by the demands of his day job.

This week, after all, will be hugely significant in Phoenix. Tomorrow night Nash leads out, for the first time, Shaquille O'Neal, who has just been traded to the Suns. The home debut of the massive O'Neal is made even more striking by the opposition - the LA Lakers, one of his former teams, who stand second in the Pacific Division. And yet, despite a voracious ambition to round off his glittering individual awards with the NBA title, Nash will be far less tense than he was when stepping across the turf at White Hart Lane early this season.

"I went out in front of the Spurs crowd at half-time against Derby," he says, blowing out his cheeks in disbelief. "Every time I get to White Hart Lane it's really special but, for a lifelong Spurs supporter, that was out of this world. I've played some big games in the NBA but I've never been so nervous. English fans can give anyone a lot of stick, especially when it's some sportsman from America they don't know anything about. But for whatever reason, probably because it's been documented ad nauseam that I'm a Tottenham supporter, they were really receptive. When they asked me on the pitch why I was such a big Spurs fan I told them my parents are from Tottenham. The whole place seemed to erupt and it was a special feeling."

John Nash, his father, played professional football in South Africa, where Nash was born, before the family emigrated to Canada. "Goal" was the first word he said as a child and as a schoolboy in British Columbia he was obsessed with football. His younger brother, Martin, has played 38 times for Canada and his sister, Joann, captained the University of Victoria football team. Nash argues that his skill and imagination as a mere 6ft 3in basketball player, dwarfed by the NBA's 7ft monsters, stem from his footballing roots.

"When I started basketball it felt to me, being able to use my hands, as if I was cheating. It was like I had an advantage because I'd been trying to do far harder things with a ball at my feet." As a young Canadian, however, he was routinely ignored by American scouts working in college basketball. His high school coach in British Columbia did not receive a single reply to the first 30 letters and videos of Nash that he sent to the United States. "I didn't have any doubts about making it," Nash shrugs. "In some respects I didn't even think about it because I had such passion. I could see no reason why I wouldn't be able to compete with anyone."

Santa Clara eventually gambled on him and since then he has been a dominant presence in American basketball, despite his relatively small physique and unusually inquiring mind. "This is my 12th season and if it was just a case of showing up at the gym and playing ball then it would still be fantastic. But the travelling, the media, the celebrity, all that stuff, takes it out of you. That's what makes it really difficult to stay fresh. But I'm really motivated by our chances this year."

Nash might be thrilled by Tottenham's prospects against Chelsea this weekend but the difference between being a fan and a competitor is underlined by the way in which his coltish delight in their Carling Cup run looks so ordinary when set against his cold-eyed resolve to win that elusive NBA championship.

"I really feel that this is the only thing missing from my career in basketball. Every year I think we have a big chance and last year we came close [losing a bruising play-off battle to the eventual winners, the San Antonio Spurs]. This season was a tough one at first. If we don't win every game we start to question ourselves but we're having fun again.

"I think you can get too focused on the championship and forget how rewarding it is to be part of a team. It's the same with Spurs. Of course I'm crazy about the idea of them winning [the final] but the important thing is that, like here, they're building something to last. So you can guess what would make my year - Spurs winning a trophy and then going all the way to the NBA championship with the Suns."